Investigation of MR Imaging With 64 Receiver Channels

64 个接收器通道的 MR 成像研究

基本信息

批准号：
6858603
负责人：
Steven M Wright
金额：
$ 18.19万
依托单位：
TEXAS A&M UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-03-01 至 2007-02-28
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): The objective of this project is to develop and characterize RF coil arrays for parallel MR Imaging at acceleration rates of up to 64 using a prototype 64 channel receiver system. Advances in gradient system and pulse sequence design have made dynamic MRI an important diagnostic tool. However, further increases in speed using conventional gradient based imaging appears limited by fundamental problems including gradient induced peripheral nerve stimulation and high RF power absorbtion rates. Parallel imaging, in which spatial localization is performed partially by the unique information contained in the reception patterns of an array of receiver coils, has become an important tool to reduce scan times without increasing gradient switching rates. These methods, known as SMASH, SENSE, SPACE-RIP and other variations, show great promise, but have only been explored to acceleration factors of 8, and 2 to 3 is more typical. This is partially due to the lack of availability of MRI systems with more than 8 receiver channels. In this project, planar and cylindrical array coils with 64 elements will be designed, fabricated and tested at the Magnetic Resonance Systems Lab on a 4.7 T scanner equipped with a 64 channel MRI receiver prototype that has been built and tested in the MRSL. Arrays will be characterized for SNR, artifact power and resolution at different levels of acceleration and imaging planes. An important feature of using the proposed large arrays is that the element size is on the order of the pixel, and differ from one another only by translation. Because of this, the point spread function of the array element itself can potentially be used to provide enhanced, or "superresolution". Superresolution techniques used in areas such as astronomical imaging and synthetic aperture radar will be investigated for their potential to provide improved spatial resolution, and sliding window techniques to provide improved spatial resolution with frame rates as high as one image per echo. both spatially and temporally, have the potential to provide improved resolution. The use of other resolution enhancement techniques including sliding window techniques will be investigated for imaging close to the array plane. It is expected that this project will advance our understanding of parallel MR imaging at very high frame rates, and provide researchers in this emerging field with data to test parallel imaging algorithms with more channels than previously available.

描述（由申请人提供）：该项目的目的是使用原型64通道接收器系统以高达64的加速速率来开发和表征RF线圈阵列，用于平行MR成像。梯度系统和脉冲序列设计的进步使动态MRI成为重要的诊断工具。但是，使用基于常规梯度的成像的进一步提高速度似乎受到基本问题的限制，包括梯度诱导的周围神经刺激和高RF功率吸收率。并行成像通过在接收器线圈阵列的接收模式中所包含的独特信息部分执行空间定位，已成为减少扫描时间而不增加梯度切换速率的重要工具。这些方法被称为Smash，Sense，Space-Rip和其他变化，显示出巨大的希望，但仅探索了8个加速度因子，而2至3则更典型。这部分是由于缺乏超过8个接收器通道的MRI系统的可用性。在这个项目中，将在配备有64个通道MRI接收器原型的4.7 T扫描仪上设计，制造和测试具有64个元素的平面和圆柱阵列线圈，并在MRSL中构建和测试。在不同级别的加速度和成像平面下，阵列将以SNR，伪影功率和分辨率为特征。使用所提出的大阵列的一个重要特征是元素大小在像素的顺序上，并且仅通过翻译彼此不同。因此，阵列元件本身的点扩散函数可以可能用于提供增强或“超分辨率”。将研究在天文成像和合成孔径雷达等领域使用的超分辨率技术，以提供改进的空间分辨率的潜力，以及滑动窗口技术，以提供改进的空间分辨率，帧速率高达每个ECHO的帧速率。在空间和时间上，都有提供改进的分辨率的潜力。将研究其他分辨率增强技术，包括滑动窗口技术，以成像接近阵列平面。预计该项目将提高我们以非常高的帧速率的平行MR成像的理解，并为该新兴领域的研究人员提供数据，以测试并行成像算法，其通道比以前更多的通道。